Milking-machine pulsator



1. L. HULBERT. MILKING MACHINE PULSATOR.

APPLICATION FILED AUG.31. I917- Patented Nov. 11, 1919.

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JOHN L. HULBERT, OF POUGHKEEPSIE, NEW YORK, ASSIGNOR TO THE DE LAVAL SEPABAT'OR COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

MILKING-MACHINE PULSATOR.

Specification of Letters Patent. Patented Nov, 11, 11919,,

Application filed August 31, 1917. Serial No. 189,065.

' tors, of which the following is a full, clear,

and exact description, reference being had to the accompanying drawings, which form a part of this specification.

My. invention relates to milking machine pulsators and particularly to that class in which there are two pneumatic motor members for moving two valve members, each valve member being adapted to supply pneumatic motive fluid for the motor attached to the other valve member. The object of my invention is to provide a pulsator, free from springs and small intricate parts, that shall be positive in action and reliable as to speed.

In the accompanying drawings, 1 have shown an embodiment of my invention that is particularly adapted for use with the cluster and teat cups shown in the patent to Mitchell No. 1,018,846, February '27, 191:2, which requires two independent pulsations.

Figure 1 is a sectional View of two cylinders and pistons and connections between them, embodying my invention.

Fig. 2 is a diagram showing my invention connected up with a cluster and a set of teat cups, a milk pail, and a vacuum line.

A cylinder a contains a piston 71 reciprocable by pneumatic motive fluid. The piston I) has two reduced diameter portions 0 and awhich, with theports e, f, g, h and 2, act as valves to supply pneumatlc motive fluid to operate a second piston j, also having two reduced diameter portions k and Z which, with the ports m, n, 0, p and 9, act as valves to supply pneumatic pulsations to a claw or cluster w, andpneumatic motive fluid to operate the piston b. In the valve 9' are two small passages r and s,'whose function is explained hereinafter. At 'u and Q) are shown throttle valves that regulate the rate of supply of air to or exhaust from the cylinder a and so control the speed of the piston b. For convenience, and to make the drawing more readily understood, openings leading direct to the atmosphere 'are marked'A, A A A the opening to vacuum 42 and the openings to the pulsation passages in the claw P and P;

In operation, when the piston b is at the top, air can enter at port e and pass out of port f and through the connected pipe j to the left end of the small cylinder, where it will press on the end of the piston j and force it to the right because air has been exhausted from the right end of the cylinder through the pipe f, the port h, port 9 and the pipe a leading to V. The small piston will then be in the position shown. Air can now enter at port 9, pass around the small diameter portion Z of the piston j and out at the port-'p, pipes 3' and a and throttle u to the upper end of the cylindero, where it presses downward on top of the. piston b- Air is at the sametime exhausted from be-' low the piston 6 through the throttle 11, pipe (If, the port 91, around the small diameter portion k of the piston valve j, and through the port 0 and pipe j to vacuum. When the' piston b is at the bottom, port 7 is in communication with port 9 to exhaustair from the left end of the small cylinder and port h is. in communication with port 1' tosupply air to the right end of the small cylinder, thus throwing the piston j to the left. With the piston j at the left, port m is in communication with port n to supply air to the bottom of the large cylinder and port ;0 is in communication with port 0 to exhaustair from the to of the large cylinder. This causes the piston b to return to the top and the cycle is completed.

When the piston valve 6, on its downward stroke, passes a central position there is some leakage from portf to g and from i to h. This leakage tends to cause a premature movement of the small piston j. The passage s in the piston j provides an escape to the vacuum port 0 for air reaching the right hand end of the piston and the passage 7' provides a supply of air from the port 9 to maintain the high pressure at the left end of the piston. The passages r and 8, while large enough to take care of leakage, are so small that their effect on the pressures when the ports a g and dare wide open is too small to interfere with prompt movement of the piston.

hen the piston j has made about twothirds of its stroke toward the left, the passage 1' is in communication with port 0 to assist in exhausting the air from the left end of valve 7' and the passage 8 is in communication with port m.t0 supply additional air to the right end of valve It is thus end with vacuum.

- seen that by the addition ofthe two passages 1' and 8 I have provided means to prevent premature beginning of movement, and means to insure complete and positive final movement, of the small piston From the pipe a leading irom port n a branch' pipe w leads to one pulsation chamber of the claw 'w and from the pipe j leadin from port. ;0 a branch pipe 10 leads to tie other pulsation chamber of the claw, so as to place one pulsation chamber in communication with vacuum and the other with the atmosphere and alternately therewith place the first, chamber in communication with the atmosphere and the secm represents a set of double-chambered teat cups connected with the pulsation chambers and vacuum chamber of the claw in a known manner. 3 represents a' milk pail connected with the "vacuum chamber of the claw w and with the vacuum pipe line 2.

By different arrangemen s of ports from the small cylinder any desired kind of pulsation may be obtained. v

While, in the embodiment of my invention herein set forth, the pneumatic pressure employed is that of the atmosphere and the exhaust is that produced by a partial vacuum, it will be understood that in the claims these expressions are used in a relative sense as meaning any two different degrees of pneumatic pressure above absolute vacuum.

Having now fully described my invention, what I desire t0 claim and protect by Letters Patent is: V

1 A milking machine pulsator compris- I ing two pneumatically operable and pneumatically interdependent members, meansincluding pneumatic connections between the two members whereby-each serves as a motor operable by motive fluid and as a valve to control the supply of motive fluid for operating the other, means to retard the movement of one member, and means to prevent premature movement of the other member by leakage of motive fluid past the re-- tarded member. 3

2. A milking machine pulsator comprising two pneumatically operable and pneumatically interdependent members, means including pneumatic connections between the two members whereby each serves as a motor operable by motive fluid and as a valve to control the supply of inotive fluid for operating the other, means to retard the movement or one member, and means to oppose prematuremovementof the other member by leakage of motive fluid past the retarded member. s

3. A milking machine pulsator comprising two pneumatically operable and pneumatically interdependent members, means including pneumatic connections between the two members whereby each serves as a motor operable'by motive fluid and as a valve to control the supply of motive fluid for operating the other, means to retard the movement of one member, and means controllable by partial movement of the other member to supply supplemental motive fluid to insure its complete movement.

4. A milking machine pulsator comprising a relatively slow moving motor member 'and a relatively quick moving motor member, there being ports and passages, controllable by the slow motor, to supply motive fluid to operate the quick motor and ports and passages, controllable by the quick motor, to supply motive fluid to operate the slow motor, there being other portsand passages controllable by the quick motor adapted to carry away leakage of the a relatively quick moving motor member and fluid passages between the same and be- -a relatively slow moving motor member and tween the pulsator and the teat cups, relativelypslow moving valves movable by the .slow motor to control, through certain of' said passages, the supply of motive fluid. to the quick motor, relatively quick moving valves movable by the quick motor to control, through certain of said passages, the supply of motive fluid to the slow motor and to supply pneumatic pulsations to the teat cups, and means operable by the quick motoradapted to neutralize the tendency for movement of the quick motor by leakage of the slow valves.

6. In a pneumatically operated milking machine, the combination, with a set of teat cups, of an automatic pulsator comprising a relatively slow moving motor member and a relatively quick moving motor member and fluid passages between the same and between the pulsator and the teat cups, relatively slow moving valves movable b the slow motor to control, through certain of said passages, the supply of motive fluid to the quick motor, relatively quick moving supply of motive fluid to the slow motor and to supply pneumatic pulsations to the teat cups, and means operable by the quick motor adapted to oppose the tendency to movement of the quick motor by leakage of the slow valves.

7. A milking machine pulsator comprising two pneumatically operable valve mem bers, one relatively quickmoving and the other relatively slow moving, means whereby each member pneun'iatically controls the operation of the other, said means including a port, connected with an operative face of the quick moving member, which the slow moving member, after movement in one direction toward a given position, connects with motive fluid, there being a port of constricted capacity communicating withsaid face of the quick moving member adapted, in the specified movement of the slow moving member, to communicate with the exhaust and thereby prevent premature movement of the quick moving member by leakage of motive fluid to said operative face before the slow moving valve reaches said position. a

8. A milking machine pulsator comprising two pneumatically operable valve mem bers, one relatively quick moving and the other relatively slow moving, means whereby each member pneumatically controls the operation of the other, said means including a port, connected with an operative face of the quick moving member, which the slow moving member, after movement in one direction toward a given position, connects with exhaust, there being a port of constricted capacity communicating with said face of the quick moving member adapted, in the specified movement of the slow moving member, to communicate with motive fluid and thereby prevent premature movement of the quick moving member by leakage of motive fluid from said operative face before the slow moving member reaches said position.

9. A milking machine pulsator comprising two pneumaticallyroperable valve members, one relatively quick moving and the other relatively slow moving, means whereby each member pneumatically controls the operation of the other, said means including ports, connected respectively with opposing operative faces of th quick moving memher. which the slow 'zncving member, after movement ineach direction toward a given position, connects respectively with motive fiuid and exhaust, there being ports of constricted capacity, communicating with said opposing faces respectively, adapted, in the specified movement of the slow moving member, to communicate respectively with exhaust and motive fluid, thereby preventing premature movement of the quick moving member by leakage of motive fluid to and from. said operative faces respectively before the slow moving member reaches said position. 7

In testimony of which invention, I have hereunto set my hand, at Poughkeepsie, N, Y., on this 24th day of August, 1917.

JOHN L. HULBERT. 

